Commercial dough production often involves production of large quantities of dough which are continuously divided into portions using various types of dividing mechanisms, such as a rotating knife or ram shear divider, into which dough is fed by motor driven dough feeding devices such as machine extruders, augers or pumps. In the case of dividing mechanisms which divide dough passing through the mechanism at a fixed interval, such as a rotating knife or ram shear divider, control of the portion size and therefore weight is achieved by controlling the operating rate of the dividing mechanism by varying the frequency or speed of the motor driving the dough feeding device, such as an electrical motor powered auger or pump. Weight control of divided dough portions has been carried out by varying control inputs to feeding device motors through the use of in-motion conveyor type checkweighing systems, such as weigh belts and weigh belt feeder systems. These apparatus, however are only capable of determining a projection of the actual static weight by collecting samples of output from a weight sensor as individual dough portions as well as the section of the conveyor belt supporting the portions pass over it. Also, as the weight samples are collected, the sensor accuracy can be affected by air currents, vibration from surrounding equipment, vibrations or harmonics generated by the dough portion's movement on the conveyor and other physical effects.
Also, since it is necessary to use a weighing device with sufficient capacity to support the weight of the empty conveyor along with the weight of the dough portion to be weighed, larger capacity weight sensors must be used, which are much less sensitive than smaller weighing sensors of the same variety.
Additionally, due to the physical properties of extruded dough, it tends to adhere to any surface it contacts. To limit the amount of adhesion it is common for flour to be sifted onto the device transporting dough portions. In prolonged operation, flour may randomly accumulate in various locations along the transport mechanism, including in the area where weight measurements are taken, thus introducing errors in the weight indications.
Further, due to the semi-solid nature of raw dough, transporting dough portions by a belt conveyor requires that the plane of the initial conveyor belt be at a higher elevation than subsequent downstream conveyor belts to eliminate the possibility of the dough portion being forced downward through the transition between sets of conveyor rollers. Also, in a system employing an in-motion belt weighing mechanism, the abrupt transition of the dough portion from an upstream conveyor to the weighing conveyor can impart an impact or torsion force to the weight sensor, resulting in inaccuracies in the measured weight.
Additionally, there are physical constraints with in-motion weighing systems, including that the weighing conveyor must be of substantial length, generally at least thirty inches, which may create integration problems with existing equipment.
Another commonly used means of weighing divided dough portions involves the use of a static weigh scale, whereby an operator may randomly remove and weigh dough portions and perform a statistical calculation to determine what adjustment may be required. This method also has several disadvantages, including that substantial variations in any individual sample portions may unduly influence the adjustment, and that removal of sample portions from the processing sequence may affect production efficiency.